Emerging data from genomic and proteomic screens suggest that many diseases have unique molecular profiles which are defining and may serve as prognostic markers. One currently unmet need in molecular imaging is the development of techniques that will allow the simultaneous imaging of a small number of such targets ("in vivo mini-arrays"). Single gene alterations are insufficient to characterize most diseases; however, using many of today's clinical imaging tools, it is difficult to assess more than one molecular parameter at a time. A second unmet need is the separation of signal intensity modulation by physiological effects (perfusion) from molecular activities in humans, in whom heterogeneity of disease may be much greater than in well characterized and well controlled animal models. The goal of this grant is to develop a modular platform approach to address both of these issues and to extend previously developed macroscopic fluorescence imaging to true in vivo multi-channel imaging (MCI) in the near infrared. We have previously shown that the near infrared window (NIR) allows acquisition of multiple independent imaging channels, that a number of distinct molecularly selective reporters can be created for diverse diseases, and that in vivo multi-channel imaging (MCI) is feasible. The proposed research will address a number of critical questions and focus on novel probe design based on a modular three component system of carrier backbone, distinct peptide linkers for multiple selectivities, and fluorochromes for independent molecular reporting; optimization of imaging/analysis to extract the greatest amount of molecular imaging content; and validation of the multi-channel approach using diverse disease models.